The open-source gnm package is published as an add-on to R, through the Comprehensive R Archive Network. It provides extensive facilities for specifying, fitting and interpreting a large class of statistical models, the generalized nonlinear models, its generality being achieved through the innovative, unified use of over-parameterized representations of models. Applications of the software are in many different research fields, including the social sciences, health sciences, agriculture, etc. A detailed manual, Generalized Nonlinear Models in R: An Overview of the gnm Package (pdf) gives many worked examples from different fields.